以DSP為基礎實現智慧型轉向控制於自動車道保持及車道變換

Abstract

□這篇論文中，使用數位訊號處理板(DSP)以嵌入式系統實現一個具有車道保持與車道變換功能的智慧型轉向控制系統，並驗證在我們的車輛平台(TAIWAN iTS-1)。發展此系統的挑戰在於整合多種系統，如影像係統、嵌入式控制器、車內感測器以及方向盤的致動馬達。車道保持的控制器所需要的車輛前方車道上與車道中心的偏移量的資訊由影像系統或是位置系統(全球定位系統)提供。而車道變□控制器經由特定的側向變加速度量來產生平順的變換軌跡，即使在沒有位置系統的情況下，車道變換控制器會將車道變換的軌跡轉換成方向盤轉角控制以進行開迴路車道變換的策略。另外為了模仿人類的駕駛行為，如在高速駕駛下平緩的轉動方向盤，我們設計一模糊增益表方式於嵌入式控制器中以用來補償原本回授控制器輸出的方向盤控制命令。此智慧型轉向控制系統已經在快速道路及與市區道路相似環境上測試成功。

In this thesis, an intelligent steering system with automated lane-keeping and lane-change functionalities is realized in an embedded system (DSP) and implemented on our vehicle platform, TAIWAN iTS-1. The developed system brings the challenge in on-line integrating various systems such as a real-time vision system, an embedded controller, in-vehicle sensors and a steering wheel (SW) actuating motor. For lane-keeping control, the required states including the relative position of the vehicle with respect to the road center at a look-ahead distance can be provided by the vision system and the location system of global position system (GPS). As to lane-change control, a smooth trajectory can be generated based on a specified lateral jerk. Even without the location system, the problem of lane-change control can be converted to a reference SW-command tracking to achieve an open-loop lane-change maneuver. In addition, to mimic human driving behavior such as smooth turning especially at high speed, a fuzzy gain scheduling (FGS) strategy is designed into the embedded controller to compensate the feedback controller by way of adapting to the SW command appropriately. The proposed intelligent steering control system has been examined on expressway and urban-like road.